New Zealand Post has cut 100 jobs across the North Island after closing a Datamail centre in Wellington.

The Petone-based centre, which prints bills and targeted mail for advertisers, will close the site in the middle of 2014, said the company in a statement.

Seventy jobs will be axed from Wellington and 30 jobs in Auckland, while 30 new roles will be created in Christchurch.

A spokesman for the state-owned company, John Tulloch, said it was throwing out old black and white laser printers, and investing in new colour printing technology.

"The significantly reduced number of printers required with the new technology means only two sites are required," said the company's spokesman John Tulloch.

"The new technology requires significantly less manual input and oversight."

Tulloch said the company needed to make the decision to remain competitive and keep its customers.

A spokesperson for the Engineering, Printing and Manufacturing Union said the job cuts were a major blow for struggling communities.

"These redundancies have come as a shock to workers and it will take a while for everyone to digest what it means.

"While we accept the restructuring is a result of new machinery being installed, we have serious concerns about the state of the job market our members will be facing and we believe this shows the need for a government strategy to tackle the jobs crisis."